Drilling and belling apparatus

ABSTRACT

Apparatus for drilling a hole, and for belling out the lower end of the hole into a conical enlargement, in a single pass of the apparatus down the drill hole, which apparatus includes a combined drilling and belling tool. Both the extension and the retraction of the belling blades are positively driven.

lli@ Il] States Patent I19I n 1I 3,794,126 Pereau [45] Feb. 26, 1974 [54] DRILLING AND BELLING APPARATUS 2,624,55I I/I953 Gamer 175/202 2,645,458 7/1953 Yost l75/202 X [75] Inventor. Robert L. Pereau, Irvine, Calif. 3096l03 7/1963 Murphy u 7S/215 X [73] Assignee: Smith International, Inc., Newport 3,112'802 2/1963 Aman et al- 175/263 X Beach Calif' 3,684,041 8/1972 Kammerer et al... V75/267 3,731,753 5/1973 Weber V75/285 [22] Fled: Aug' 23 1973 FOREIGN PATENTS 0R APPLICATIONS [21] APPL N0# 391,008 1,086,534 10/1967 Great Britain I75/2I5 Related U.S. Application Data 260,527 4/l970 U.S.SR l75/267 62 D"l fS .N .177,037,0 .l,l97l,P .N. l l 3`l7v5ls7lgl7g er O Ct at o Primary Examiner- David H` Brown {52} U.S. Cl 175/173, 175/202, 175/215, [57] ABSTRACT 5l l t Cl Ezll// Apparatus for drilling a hole, and for belling out the 58] Fl? id 267 207 lower end of the hole into a conical enlargement, in a l le 0 care 175/284 285 173 single pass of the apparatus down the drill hole, which apparatus includes a combined drilling and belling (56] References Cited tool' UNITED STATES PATENTS Both the extension and the retractlon of the bellmg blades are positively driven. 373,440 ll/l887 Chapman et al 175/215 987,266 3/l9ll Smith 175/202 X 3. Claims, 6 Drawing Figures PAIENIEUFEBzelSM SHEET 3 F 3 DRILLING AND BELLING APPARATUS The present application is a division of my prior copending application Ser. No. 177,037, now U.S. Pat. No. 3,757,876 filed Sept. l, 1971 and assigned to the same assignee.

BACKGROUND OF THE INVENTION In construction work it is often the practice to construct a footing or foundation member whose lower end portion is enlarged. Such footings are commonly constructed of reinforced concrete in which the steel rein' forcing material provides the tensile strength which would otherwise be lacking. Enlargement of the lower end of the footing not only adds to the weight and hence the stability of the footing, but also provides a positive restraint against any upward pull on the footmg.

One particular application of the present invention is in the construction of ocean platforms to be used for oil prospecting or drilling operations. The ocean platform may be subjected to very strong ocean waves which place severe stresses on the platform legs in both horizontal and vertically upward directions. Furthermore, the work of constructing such a platform must be performed under conditions which are rather adverse, hence there is a high premium on efficiency in the initial performance of the construction work.

The art of drilling holes for reinforced footngs, whether on land or under the ocean floor, has hitherto been well known. It has also been well known, after the initial hole has been drilled, to bell out or enlarge tlle lower end of the hole. However, the belling out of the lower end of the hole has always required a separate and distinct operation.

The principal object and purpose of the present invention, therefore, is to provide drilling and belling apparatus which is suitable for drilling a hole and then belling out its lower end, all in a single pass of the tool down the hole.

A more specific object of the invention is to provide such an apparatus which is suitable for use in constructing an ocean platform.

DRAWING SUMMARY FIG. 1 is an elevational view of footings supporting a temporary ocean platform, in a typical ocean platform construction job where the apparatus of the present invention may be used;

FIGS. 2a, 2b and 2c together are in an elevation view of the apparatus of the present invention, shown in use in the center of FIG. l for constructing a footing;

FIG. 3 is an elevational view of the combined drilling and belling tool with blades extended; and

FIG. 4 is an enlarged detailed view showing the tooth locations for the belling blades.

PREFERRED EMBODIMENT GENERAL DESCRIPTION Some of the essential material for disclosing the present invention is incorporated by reference to my prior copending application, now U.S. Pat. No. 3,757,876, in accordance with the procedure specifically authorized in Manual of Patent Examining Procedure, Section 608.01(p).

The combination drilling and belling tool assembly, FIGS. 2a, 2b, and 2c, consists of a combination drilling and belling bucket 500, the necessary sections of reverse circulation drill stem with airlift 300, a section of reverse circulation drill stem with air injection 400, the necessary number of stabilizers 375, a kelly bar assembly 200, and a swivel 100.

Referring to FIG. 1, in order to make the tool operational it is also necessary to have compressed air and hydraulic fluid supplies (not shown), a settling tank 14 into which the drilling fluid 22 and drilling chips may be discharged, a return hose 16 for returning the drilling fluid to the drill hole, a tower 18 and block and tackle 24 to support the drill string during the drilling operation, a winch 26 to control the block and tackle, and a ring gear drive or rotary table 20 which engages the kelly bar 200, and provides the rotary driving force to the drill stem assembly.

Referring to FIGS. 2a, 2b, 2c, (and 3a of the patent), attached to the top of the kelly bar and drill stem assembly is a reverse circulation swivel consisting of a bail 102, a swivel body 104, and elbow 106 attached to the top of the swivel body, a spindle 108, and a hydraulic swivel housing 110. The bail is provided with a means for pivotally attaching a block and tackle hook 28 at its top and is further provided with a means for the pivotal attachment of the swivel body 104 to its lower end. The spindle is centrally disposed within the swivel body and has a spindle center pipe 112 with a swivel flange plate 114 attached to its lower end. The swivel body is provided with a sealed cavity 118 sur rounding the center pipe of the spindle and connected in a continuous manner to an auxiliary conduit 158 in the spindle. In addition, the purpose of the swivel is to provide the vertical support necessary to support the drill tool while still allowing the spindle to freely rotate within the swivel body. The elbow 106 attached to the top of the swivel body has an elbow-shaped pipe 120 which acts as a discharge nozzle for the drilling fluid and drilling chips. It should be noted that the vertical displacement of the entire drill string is controlled by the vertical displacement of the swivel. The vertical displacement of the swivel is generally controlled by the attachment of a block and tackle 24 between the top of the drilling tower 18 and the top of the swivel bail 102.

Attached between the top of the drill stem assembly and the swivel is a kelly bar assembly 200. The kelly bar assembly has an elongated tubular frame 202, a center pipe section 204 and an air auxiliary pipe section 206 (FIG. 3b of the patent), disposed within the tubular frame, two elongated ribs 208 attached to the outer circumference of the tubular frame, two hydraulic cylinders 210 disposed within the frame, a bracket 212 for coupling the action of the two hydraulic cylinders together, a sucker rod swivel 214 for attachment of the drill stem sucker rod 209 to the hydraulic cylinder bracket 212, and top and bottom adapters 216 and 218 at the top and bottom ends of the kelly bar for attaching the kelly bar assembly 200 between the top of the drill stem assembly and the swivel 100.

The function of the kelly bar assembly 200 is to provide a means for coupling the drill assembly to the rotary cable 20. This coupling is provided by the elongated ribs 208 on the outside of the kelly bar frame. The kelly bar is free to slide up and down through the rotary table while recesses within the rotary table ring gear engage with the ribs on the outside surface of the kelly bar assembly. Hence, the power drive provided by the rotary table is transmitted to the kelly bar which in turn transmits the rotary action to the drill stem assembly. The two hydraulic cylinders 210 disposed within the kelly bar frame are coupled at their upper or cylinder ends to the frame structure while the lower or piston ends of the cylinders are coupled to the bracket 212, which in turn is coupled to the sucker rod swivel 214. This sucker rod swivel provides connection to the previously mentioned sucker rod 209 which extends up through the drill stem. Hence, by activating the hydraulic cylinders the sucker rod is displaced in a vertical direction relative to the kelly bar and drill stem assemblies.

Attached to the bottom end of the kelly bar assembly is a section of reverse circulation drill stem with airlift 300. lt is seen that this section of drill stern consists of a center pipe section 302, two auxiliary pipe sections 304 (FIG. 9a ofthe patent), a tubular casing 306, four transverse openings 308 through the casing, and attachment or drill stern flange plates 310 and 312 at the upper and lower ends of the drill stem section. The center pipe section and auxiliary pipe sections are so oriented that they align with the center pipe section, the auxiliary air pipe section and the sucker rod swivel of the kelly bar assembly.

At least one section of reverse circulation drill stem with air injection 400 is used in the drill string. This section of drill stem is nearly identical to the previously described section of reverse circulation drill stern with airlift 300. lts main components are a center pipe section 402, two auxiliary pipes 404 and 406 (FIGS. 9a and 9b of the patent), a tubular casing 410, attachment or drill stem flange plates 412 and 414 at its upper and lower ends, and four transverse openings 416 through the casing. As with the previously described section of drill stem, one of the auxiliary pipes 406 shown in FIG. 9b may be used to house a section of sucker rod 209. This auxiliary pipe is identified as the sucker rod auxiliary pipe. The essential difference between this section of drill stem and the previously described section of drill stem is revealed by examining the function of the other auxiliary pipe 404. At the lower end of the drill stem section is seen a series of drilled holes 418 interconnecting the auxiliary pipe 404 and the center pipe 402 of the drill stem. Hence, as air pressure is applied to this auxiliary pipe it will necessarily flow through these holes into the center pipe. This is known in the art as an air injection process.

Attached at regular intervals along the drill string are stabilizers 375. The stabilizer is a commercially available item and basically consists ofa spindle 377 and an outer housing or body assembly 379. The body assembly may be provided with a series of elongated roller bearings such that the body assembly is freely rotatable relative to the spindle. The outside diameter of the body assembly is made to match the diameter of the drill casing 50 and the inside diameter of the spindle is made to be firmly attached to the drill stem. Hence, when the stabilizer is firmly attached to the drill stem it acts to center the drill stem within the drill casing. The provision of the elongated roller bearings acting between the spindle and the stabilizer houding allows the drill stem to freely turn within the stabilizer housing while the stabilizer housing is riding against the drill casing.

The attached sections of drill stem make up the drill stem assembly. Attached to the bottom of the drill stem assembly is the combination drilling and belling bucket 500. The combination drilling and belling bucket 500 consists of an elongated generally cylindrical bucket frame 502, two belling blades 508 and 509 (FIG. 3), two actuating arms 510 and 511, a carriage assembly 512, and an elongated member 514 attached to the carriage assembly. The bucket frame is seen to consist of an outer shell assembly 504 which is provided with recesses, i.e., rectangular cutouts 522 and 523, for receiving the belling blades. At the bottom of the outer shell assembly is attached a drilling bucket bottom 546. This bucket bottom is a standard drilling bucket bottom and is provided with drilling blades for cutting and removing the soil from within the drill casing 50 as the bucket is rotated in a clockwise direction. The bucket frame outer shell assembly is provided with means for pivotally attaching the belling blades. These pivotal attachments are so oriented that the blades are positioned within the recesses provided in the outer shell of the frame. The remaining portion of the frame structure is provided by the drill stem assembly 506 which is centrally disposed within the outer shell assembly and is rigidily attached to its upper end. This drill stem assembly has a center pipe 552 which extends to the bottom of the bucket. Disposed between the bucket frame and the center pipe is the carriage assembly 512. The carriage assembly may be vertically displaced relative to the bucket frame. Extending between the carriage frame and each belling blade are two actuating arms 510, 511. One end of each of the actuating arms is pivotally attached to the lower end of the carriage frame. The other end of each of the actuating arms is pivotally attached to its respective belling bucket blade 508 or 509 near the blade longitudinal midpoint. As previously noted, the belling blade is pivotally attached at its upper end to the bucket frame and is so oriented that the lower end of the belling blade is free to swing into and out of the recess provided in the outer shell of the bucket frame. Attached to the upper end of the carriage assembly is an elongated member 514. This elongated member passes through the bucket drill stem assembly 506 and terminates at the upper end of the bucket drill stem.

From the foregoing description it will be apparent that the operation of the belling blades is controlled by the selective raising and lowering of the carriage assembly. Referring to FIG. 3, the selective raising and lowering of the carriage assembly 512 is accomplished by selectively raising and lowering the elongated member 514. As the carriage assembly is raised, the ends ofthe actuating arms 510 attached to the carriage assembly are also raised. Because the actuating arm is a rigid member, the structure attached to its other end, that is, the belling blades 508 and 509, must act to accommodate the upward movement of the actuating arm. The only way in which the blade can do this is by rotating about the pivotal attachment at its upper end. Hence, as the carriage assembly is raised the belling blade lower end is moved through an arcuate path away from the bucket frame. As the carriage assembly is lowered the blades are retracted into the recesses within the bucket frame.

In operation, the primary advantage of this tool is that with a single pass a drill hole of the desired diameter may be drilled to any desired depth and then without removing the tool a conical cavity may be cut at the lower end of the drill hole. Briefly the procedure for doing this is to drill down the desired depth by concurrently rotating and lowering the drill stem. lt is necessary to add sections of the reverse circulation drill stem with airlift 300 as the drill string lowered, and at selected intervals to also add the stabilizers 375. During the drilling process, drilling chip removal is accomplished by the reverse circulation process. ln this process pressurized air is connected-to the swivel 100. Referring to FIGS. 3b, 9a, and 9b of the patent, this air pressure is supplied through the swivel to kelly bar air auxiliary pipe section 206 and hence to one of the drill stem auxiliary pipes 304. Upon reaching the reverse circulation drill stem with air injection 400, the air is then injected into the center pipe of the drill stem, through the series of drilled holes 418. The air then bubbles up through the center pipes 402 and 302 of the drill stem and kelly bar center pipe 204 into the swivel 100, FIG. 3 of the patent, and through the elbow discharge nozzle ll to the settling tank 14, FIG. 1. This air flow creates lift in the center pipe which in turn lifts the drilling fluid from the bottom of the drilling bucket 50 and carries with it the drilling chips as they are cut from the bottom of the drill hole. In this manner, the drilling fluid is carried up through the center pipes of the drill stern and kelly bar to the swivel center pipe and through the discharge nozzle to the settling tank. Drilling fluid is then returned to the drill hole after the drilling chips have settled out. In this manner a reverse circulation is set up whereby the fluid flows down the outside of the drill stem assembly to the bottom of the drill hole and then returns through the center of the drill stem assembly to the settling tank carrying with it the drilling chips.

Once the desired depth of the drill hole is reached, the lowering of the drill string is stopped and the rotation is reversed to the counterclockwise direction. The hydraulic cylinders 210 in the kelly bar assembly 200 are then actuated to pull the sucker rod 209 in a vertical direction. Since the sucker rod 209 is attached to the elongated member 514 of the combination drilling and belling bucket 500, which in turn is attached to the carriage assembly 512, the vertical displacement of the hydraulic cylinders 210 causes the vertical displacement of the carriage assembly 512 relative to the bucket frame S02. As has been previously described, this action causes the belling blades 508 and S09 to extend and, since the rotation of the bucket 500 is continued, the belling blades cut a conical cavity at the bottom of the drill hole. During this entire process the air injection procedure is continued, thereby effecting the drilling chip removal in the manner just described. Once the blades have been fully extended, the direction of the hydraulic cylinder travel is reversed causing the sucker rod 209 to reverse the direction of the travel of the carriage assembly 512, thereby causing a reversal in the direction of the blade movement. This is continued until the blades are fully returned into the recesses in the bucket frame 502. At this point the drill hole is completed, and the entire drill stem assembly and bucket are removed from the drill hole.

What is claimed is:

1. Apparatus adapted for use with a casing that has been driven into the ocean floor, for first drilling out the material of the ocean floor that is retained within the casing, then extending the hole beyond the lower- Ymost end of the casing, and thereafter belling out the extended portion of the hole into a conical configuration, in a single operation without removal of the apparatus from the casing, comprising:

a combined drilling and belling tool having a lower end constituting a drilling bucket bottom, a plurality of belling blades which extend vertically above the drilling bucket bottom and are radially disposed around the tool and have their upper ends pivotally supported from the tool, a carriage contained within the tool within the confines of the belling blades, a plurality of actuating arms having their inner ends pivotally coupled to said carriage and their outer ends pivotally coupled to the centrai longitudinal portions of respective ones of said belling blades, said carriage being vertically reciprocable for selectively extending the lower ends of said belling blades away form said tool;

a drill string coupled to the upper end of said tool for drivingly rotating the s'ame as it is progressively lowered, said drill string including first and second conduits providing a circulating loop path for the forced removal of drilling cuttings from the hole, said drill string also including an auxiliary housing for an actuating member;

an elongated rigid actuator member occupying said housing and extending the full length of said drill string and having its lower end connected to said carriage of said tool for selectively raising or lowering the same;

a kelly bar assembly coupled to the upper end of said drill string, said kelly bar assembly containing vertical drive means which is coupled to the upper end of said elongated rigid actuating member for selectively raising or lowering the same;

and a swivel assembly coupled to the upper end of said kelly bar assembly, both said swivel assembly and said kelly bar assembly containing extensions of said first and second conduits of said circulating loop system, and said swivel assembly further containing means for energizing said vertical drive means of said kelly bar assembly.

2. Apparatus as claimed in claim 1 wherein the teeth of said drilling bucket bottom are adapted for a cutting action in one direction of rotation, and said belling blades are adapted for cutting action in the opposite direction of rotation.

3. The apparatus claimed in claim l wherein the length of said belling blades is approximately five times the diameter of said combination tool, and said vertical drive means and elongated rigid actuating member are adapted for raising said carriage a sufficient distance so as to extend the lowermost ends of said belling blades to form a radius which is approximately five times the radius of said combination tool. 

1. Apparatus adapted for use with a casing that has been driven into the ocean floor, for first drilling out the material of the ocean floor that is retained within the casing, then extending the hole beyond the lowermost end of the casing, and thereafter belling out the extended portion of the hole into a conical configuration, in a single operation without removal of the apparatus from the casing, comprising: a combined drilling and belling tool having a lower end constituting a drilling bucket bottom, a plurality of belling blades which extend vertically above the drilling bucket bottom and are radially disposed around the tool and have their upper ends pivotally supported from the tool, a carriage contained within the tool within the confines of the belling blades, a plurality of actuating arms having their inner ends pivotally coupled to said carriage and their outer ends pivotally coupled to the central longitudinal portions of respective ones of said belling blades, said carriage being vertically reciprocable for selectively extending the lower ends of said belling blades away form said tool; a drill string coupled to the upper end of said tool for drivingly rotating the same as it is progressively lowered, said drill string including first and second conduits providing a circulating loop path for the forced removal of drilling cuttings from the hole, said drill string also including an auxiliary housing for an actuating member; an elongated rigid actuator member occupying said housing and extending the full length of said drill string and having its lower end connected to said carriage of said tool for selectively raising or lowering the same; a kelly bar assembly coupled to the upper end of said drill string, said kelly bar assembly containing vertical drive means which is coupled to the upper end Of said elongated rigid actuating member for selectively raising or lowering the same; and a swivel assembly coupled to the upper end of said kelly bar assembly, both said swivel assembly and said kelly bar assembly containing extensions of said first and second conduits of said circulating loop system, and said swivel assembly further containing means for energizing said vertical drive means of said kelly bar assembly.
 2. Apparatus as claimed in claim 1 wherein the teeth of said drilling bucket bottom are adapted for a cutting action in one direction of rotation, and said belling blades are adapted for cutting action in the opposite direction of rotation.
 3. The apparatus claimed in claim 1 wherein the length of said belling blades is approximately five times the diameter of said combination tool, and said vertical drive means and elongated rigid actuating member are adapted for raising said carriage a sufficient distance so as to extend the lowermost ends of said belling blades to form a radius which is approximately five times the radius of said combination tool. 